Hay conditioners generally include a pair of rollers mounted in co-extensive parallel relationship for rotation about respective axes with the crop arranged to pass between the rollers in a conditioning action.
Some rollers provide a rubber or other elastomeric material at the surface where each of the rollers have sequential ribs and recesses around the periphery so that the ribs of one mesh into the recesses of the other while the rollers are in contact to provide pressure between the surfaces while they contact.
Such elastomeric rollers have been found to provide an effective conditioning action but are prone to wear and damage. Metal rollers with metal flutes are preferred for more effective wear characteristics but the conditioning effect must occur without contact and pressure between the rollers since the noise of contact and the undesirable cutting action on the crop material should be avoided.
Each of the metal rollers carries a plurality of longitudinally extending angularly spaced flutes which project outwardly from the surface of the roller. The rollers are spaced by a distance such that the flutes intermesh generally without contact between the rollers. The intermeshing of the flutes causes the crop material to be bent as it passes between the rollers causing a cracking of the waxy surface of the crop stem.
It is necessary in such rollers to allow one of the rollers, generally the top roller, to move in a direction to increase the spacing between the axes of the rollers to accommodate different amounts of crop material passing between the rollers and to accommodate obstacles such as stones and sticks which pass through without damage to the rollers. Generally this movement is provided by suspending each end of the top roller on a spring biasing system which allows each end independently to rise and lower in a floating action.
In view of the fact that the rollers carry intermeshing flutes, it is necessary to ensure that the rollers are driven in synchronism at all times including accommodating the lifting movement while synchronism is maintained.
A number of previous designs have been proposed and manufactured to provide the drive from the first roller to the second roller to maintain the necessary synchronism. One arrangement includes a gear box having an input attached to the bottom roller and an output shaft attached to the top roller. The output shaft includes universal joints which allows the output shaft to accommodate the up and down movement of the top roller shaft. The gear box arrangement is expensive and is of relatively wide width.
An alternative arrangement includes a double chain drive system. In this system, a drive sprocket on the end of the bottom roller and two idler sprockets are located in a common plane at right angle to the axis of the bottom roller at the apexes of a triangle. A chain wrapped around these three sprockets engages a fourth sprocket driven by the chain between the drive sprocket and one of the idler sprockets. A second chain communicates drive from a fifth sprocket coaxial with and co-rotatable with the fourth sprocket to a driven sprocket on the end of the top roller. The top roller is then positioned within the apexes defining the triangle and can pivot relative to the axis of the fourth and fifth sprocket. This arrangement is highly complex involving a high number of idler sprockets thus increasing cost and increasing chain wear. The double chain arrangement also significantly increases the width of the device since it must accommodate the two chains side by side.
A yet further arrangement is shown in U.S. Pat. No. 5,435,239 (Talbot) issued Jul. 25, 1995 and assigned to the present assignees. This shows a particular chain driving system which communicates drive from the bottom roller to the top roller while ensuring the proper synchronism despite changes in spacing between the rollers, while acting to minimize the size and complexity of the drive system.
However there remains a requirement to yet further increase the length of the rollers to maximize crop throughput and to minimize the amount of crop per unit length to obtain the best conditioning action on the crop. At the same time, the amount of space available is limited by the geometry of the supporting machine, and in some designs the conditioner is located between two spaced support legs of the frame of the machine which are set at a distance which cannot readily be changed. The only way therefore to increase the length of the rollers is to reduce the width of the drive system which must be accommodated at the end of the rollers between the legs. Attempts, such as that in the above Talbot patent have been made therefore for many years to minimize the complexity of the drive and therefore its dimension.
Prior U.S. Pat. No. 6,220,007 (Doerr) assigned to Vermeer, U.S. Pat. No. 5,056,302 issued Oct. 15, 1991 (Rosenbalm) assigned to Deere and U.S. Pat. No. 5,357,737 issued Oct. 25, 1994 (Ermacora) assigned to Kuhn all provide a design using meshing gears which connect from a gear on the driven bottom roller through idler gears to a driven gear on the top roller. In all these patents the top roller is mounted for movement in an arc about a pivot point. The gear arrangement is designed to minimize or reduce changes in angular timing between the rollers as they rotate while the distance between them is varying.
In Canadian Application 2,406,419 filed Oct. 4, 2002 and published in April 2004 by the present Assignees is disclosed an arrangement in which timing is communicated between the rollers by a resilient rubber star wheel on one of the rollers which meshes with a rigid gear wheel on the other. This arrangement has not proven to be successful.
At the same time, the shape and arrangement of the flutes must be selected to ensure effective conditioning. The above Talbot patent shows flutes which are simple rectangular bars welded on the exterior of the roller surface. These can be for example ⅜ inch wide by 1.0 inch high or 0.75 inch wide by 1.0 inch high. Another example of flute shape is provided simply by 90 degree symmetrical angle irons with the legs welded onto the roller surface so that the flute provides an inverted V-shape projecting from the surface. A further example has the same general V-shape but the legs are curved outwardly to simulate an involute shape. It has been generally believed that the action is merely one of bending the crop stem back and forth between the points of the intermeshing flutes so as to crack the stem. However close attention is currently being applied to improving the action so that the drying of the crop occurs more rapidly without cutting the crop into short lengths. The action of the rubber crushing rollers is known to be effective in crushing the stems into a flat condition which encourages drying by longitudinal cracking. In another example metal rollers are followed by a pair of rubber rollers in a compound system. While this may provide improved conditioning action, the cost of such a complex system may be prohibitive.
In U.S. Pat. No. 6,346,067 (Walters) is disclosed a conditioner roller which has a channel member crimped along a center line to form a groove which contains screw fasteners by which the channel member is removably bolted to the outside of the roller for ready replacement. The shape of the flute and its cooperation with the opposite roller is not discussed and presumably is not of interest.
In general, the following points are desirable for a crop conditioner:
Should condition crop to help the crop dry fast so it can be harvested sooner with less degradation in feed value.
Should have a minimum of cut off leaves and fine stems that will end up as harvesting losses and will lower the feed value.
Should have the ability to set the degree of conditioning by adjusting the degree of intermesh and angular timing for different crops or conditions.
Should feed well, that is the ability to pull in crop.
Should be durable.
Should leave crop with enough structural integrity to form a porous windrow that allows air movement to facilitate dry-down.
Basically, as set out above, two types of intermeshing roll type conditioners are popular on the market. One is intermeshing bars that provide crimp marks (sharp bends) by folding the crop over a bar. The others are elastomer (rubber or recycled tire materials) that operate at tighter clearances to squeeze the crop stems producing cracks or crushes along the length of the stems.
The crushing or cracking down the length of the stems tends to allow the individual stems to dry faster than crimping style. However this style rolls have the disadvantage of poorer feeding and leave the crop stems with less structural integrity that results in more dense and less even windrows in some conditions. They also more damage to the crop if they are set too aggressively or are feeding poorly. In some crops they feed so poorly that it is not practical to use them at all. Also, the durability of the elastomer rolls is generally much poorer than steel rolls.
Crimping style bars such as the v-bars shown in the attached pictures tend to be more gentle as long as they are set correctly for the crop. To tight an intermesh can result in greater losses due to more chopping of the crop. (Note the sharp corner is most prominent at the timing point that produces the greatest deflection of crop.)